Not asking how women with very new infections got HIV

Two studies find 100 very new HIV infections in women in Africa

At least two studies in Africa enrolled and followed HIV-negative women, taking and testing blood for virus two times per week to find people with very new infections.[1,2]

2012-16, researchers in KwaZulu-Natal, South Africa, enrolled and followed 945 HIV-negative women aged 20-22 years. The study found 42 new infections; in 36 women, infections were very new: the study found virus in women’s blood only 3-7 days after a previous test found no virus.[1]

In 2009-15, researchers identified 58 women with very new infections in Kenya, Tanzania, and Uganda. From published data on a subset of infections, the study found virus in blood only 3-7 days after a previous test found no HIV. (The same study identified 2 very new infections in women in Thailand and 52 in men who have sex with men [MSM] in Uganda and Thailand and transgender women in Thailand.)[2]

Purpose of the studies

The studies were designed to monitor what happens in early HIV infections — what the virus does, how the body reacts.

Studies were also designed to look for risks. Researchers in KwaZulu-Natal proposed to study “…behavioral risk factors for HIV acquisition…”(page e36 in [1]). A primary objective of the multi-country study (Kenya, Tanzania, Uganda) was to “Define the risk behavior” (Supplementary material, Protocol, page 49 in [2]).

What the studies could have done to find out how women got HIV

The best current estimates are that tests can find virus in someone’s blood 8-14 days after the event that got HIV into their body.[3-5] Because the two studies found most new infections 3-7 days after a previous blood test did not find HIV, the best estimate is that studies found most new infections 8-21 days after the event that got HIV into their body.

If asked, women could be expected to remember specific sex or skin-piercing events in the previous weeks that might have gotten HIV into their bodies. Did studies look for events? There is no evidence either study asked about or even considered skin-piercing events in healthcare and cosmetic services. As for sex, there is similarly no evidence either study asked women to identify possible events or traced and tested partners. Tracing and testing should have been easy in KwaZulu-Natal, but may have been more difficult for many women in Kenya, Tanzania, and Uganda:

KwaZulu-Natal: Women in KwaZulu-Natal had modest sex lives. At the beginning of the study: 96% of women reported a steady partner, but only 3% lived with him; women reported 1-3 lifetime partners; 24% always used condoms. After the study had been going for three months, only 73% reported having sex in the previous 30 days.

Kenya, Tanzania, and Uganda: Across the three countries, at the beginning of the study: a majority of women exchanged goods for sex, and most reported more than three sex partners in the previous three months.

What was missed with incomplete research?

Public health loss: The studies provided no information about the relative importance of sex vs. blood risks in Africa’s HIV epidemics. In KwaZulu-Natal, women in the study got HIV at the rate of 8.2% per year, much faster than could reasonably be expected from sex. Failure to trace and test sex partners or to ask about skin-piercing events leaves women in KwaZulu-Natal with unknown risks. In Kenya, Tanzania, and Uganda, women got HIV at the rate of 2.6% per year. Many women were sex workers, with both sex and blood risks (injections, etc) that come with the trade. In most countries outside Africa, prostitutes who are not also injection drug users have very little HIV.

Leaving partners at risk: When doctors find someone with a new HIV infection, it’s good practice (good ethics) to trace and test sex partners. If the partner is HIV-negative, this gives the couple a chance to protect the partner with condoms. Both studies left HIV-negative steady partners at risk.

Scientific loss: Not measuring time from HIV entry to identifiable infection: The best current estimates of the time from HIV entry to a recognizable infection (enough virus in blood to show up in a test) are based on several series of blood samples from plasma donors. These estimates are based on mathematical models with assumptions about how fast HIV multiplies after entering the body, without knowing anything about the events that infected the donors: Did donors get HIV from anal sex, vaginal sex, injection drug use? When did they get HIV into their bodies?

The two studies in Africa that together identified 100 new infections — most of them very new, within weeks after HIV entered women’s bodies — provided opportunities to resolve questions about early HIV infection processes. Does the time from virus entry to virus showing up in blood test depend on how the virus entered the body (note: tests were able to see virus in blood if there were at least 20-30 copies per millileter[6,7])? If virus goes directly into blood through a skin-piercing event, does the infection develop faster than if virus enters through the vagina? No one looked, so we still don’t know.